An aim of the invention is to provide an operating mechanism capable of performing a rapid open-close-open cycle (a cycle comprising in succession: circuit-breaker opening, circuit-breaker closing and circuit-breaker opening a second time), followed after a suitable time delay (for example not less than 15 seconds) by a rapid close-open cycle (i.e. a cycle comprising: circuit-breaker closing followed by circuit-breaker opening).
U.S. Pat. No. 4,162,385 describes a two-spring control mechanism capable of performing the above-mentioned cycle. A drawback of this prior art device lies in the energy stored in the springs being transmitted from one spring to the other, as well as being transmitted to the circuit-breaker operating member with transmission taking place via links hinged on various shafts. Unfortunately, high tension circuit-breakers, and in particular puffer circuit-breakers require the contacts to move rapidly so that the opening and closing operating time for the contacts is as short as possible. This makes it important for the operating mechanism to be disposed as close as possible to the drive rod for transmitting the operating motion.
An aim of the invention is to provide an operating mechanism in which energy is transferred from one spring to the other and from the springs to the moving rod without passing through links, rods, or other motion-transmitting components.
Another aim of the invention is to provide an operating mechanism in which the "energy-storage" and the "action" functions are physically separable, in particular so as to be able to remotely control circuit-breaker without having to use mechanical members for transmitting rapid engagement and disengagement motions.